1. Field of the Invention
The present invention relates to a recording apparatus including an inkjet recording head.
2. Description of the Related Art
Japanese Patent Laid-Open No. 2006-44021 discloses a method of supplying a humidified gas to the vicinity of ink nozzles in a printer including a plurality of inkjet recording heads arranged in a conveying direction to prevent the nozzles from drying. In this printer, each space between two adjacent recording heads is filled with a supporting member so that the recording heads are flush with the supporting member, thus providing a narrow gap region extending over a predetermined distance. A highly humidified gas is supplied into the gap region, thus humidifying each recording head to prevent the head from drying.
In the printer disclosed in Japanese Patent Laid-Open No. 2006-44021, a unit that holds and conveys a sheet is an attraction belt or attraction roller which holds the sheet while attracting the rear surface of the sheet using a method of electrostatic attraction or vacuum attraction. In some cases, however, poor attraction occurs depending on the kind or properties of a sheet to be used because only the rear surface of the sheet is held. Particularly, in the printer disclosed in Japanese Patent Laid-Open No. 2006-44021, since the highly humidified gas is introduced to the attraction belt or attraction roller, charges escape from the attracted surface due to humidity. Disadvantageously, holding force is remarkably reduced. As for a sheet having high stiffness and a tight curl, therefore, it is difficult to hold the sheet by attracting only the rear surface thereof, so that the sheet partially floats. The quality of an image recorded on a floating portion is degraded. If the amount of floating of the sheet is large, the sheet may come into contact with the recording heads. When the method of vacuum attraction is used to hold the sheet in the printer disclosed in Japanese Patent Laid-Open No. 2006-44021, the introduced humidified gas is sucked by vacuum before the sheet is attracted, the efficiency of humidification remarkably degrades.
As a unit configured to hold and convey a sheet in a recording location, a pair of rollers nipping the sheet therebetween may be used. However, when one of the rollers is positioned adjacent to the recording heads, the current of the introduced humidified gas is blocked by the roller. Accordingly, it is not easy to set the humidity in the whole space between the recording heads and the sheet to a desired value in a short time. Regarding the recording heads, as the recording head is farther away from the side from which the humidified gas is introduced, humidifying the recording head is later. Accordingly, it takes time until an environment in which all of the recording heads are properly moisturized is provided. This may become a factor that increases a start-up time of the apparatus.